1. Field of the Invention
The present invention relates to a gas turbine, more specifically the gas turbine equipped with a sealing device for preventing combustion gas from entering a wheel space.
2. Description of the Related Art
In a gas turbine including a compressor, a combustor, and a turbine, air compressed by the compressor is burned to be high-temperature combustion gas along with fuel after the compressed gas is supplied to the combustor. This combustion gas passes through the turbine to expand therein, which rotates a rotor blade rotating together with a rotor, thereby rotating a shaft.
The rotor blade of the turbine exposed to the high-temperature combustion gas is designed with high-temperature-resistant specifications. Since the rotor is not designed with such specifications, it is necessary to prevent the high-temperature combustion gas from entering the wheel space, which can be achieved, for example, by installing a seal fin on a rotor blade shank portion, and then supplying pressurized air from the compressor to the wheel space to purge the combustion gas.
The sealing device as above includes a gas turbine sealing device whose seal portion is configured from the seal fin and a honeycomb seal in order to reduce an amount of cooling air leaking toward a high-temperature combustion gas side, thereby preventing performance degradation of the gas turbine. The seal fin is provided on the upper portion of a seal plate that is mounted on an end of a platform of the rotor blade. The honeycomb seal is located on a bottom surface of an end of an inside shroud of a stator blade. Refer to JP-10-252412-A.